Mechanisms and Potential Applications of Technologies for Detecting Specific Polyfluoroalkyl Substances via Nano-level Interactions

Abstract

Per- and polyfluoroalkyl substances, possessing chemically and thermally stable C-F bonds, have been widely used in various products owing to their flame retardancy, chemical resistance, and water- and oil-repellent characteristics. Among these, some perfluoroalkyl substances (‘specific PFAS’) are beginning to raise concerns regarding their potential toxicity to living organisms and bioaccumulation. Recently, specific PFAS originating from fire-extinguishing foam, wastewater from semiconductor manufacturing plants, and fluororesin-coated waste have been detected in aqueous environments worldwide. These species mainly present at low concentrations (parts-per-trillion (ppt) level) and have prompted stringent regulations, such as drinking water standards. Liquid chromatography–tandem mass spectrometry remains the gold standard for detecting specific PFAS at the ppt level. However, its implementation necessitates skilled handling and long analysis durations. To address these problems, based on interactions with specific PFAS at the nano-level, there has been active development of materials aimed at detecting specific PFAS with high sensitivity, simply, and in a short time. Several materials capable of detecting specific PFAS at parts-per-billion (ppb) to parts-per-million (ppm) levels are already undergoing verification research with a view to practical application. Nevertheless, the detection technologies of specific PFAS at the ppt level in actual aqueous environments remains challenging owing to limited selectivity against contaminants and difficulty in widespread on-site detection. This review provides a comprehensive overview of detection material and technologies for specific PFAS. Moreover, we comprehensively discuss the detection mechanisms and sensing performance of specific PFAS detection materials, as well as issues facing practical application, and present future prospects for materials and material development aimed at the simple, rapid, and highly sensitive detection of specific PFAS.